[PATCH v8 13/15] tpm: Add sysfs interface to allow setting and querying the preferred locality

Ross Philipson
2024-02-14T22:36:48Z

Expose a sysfs interface to allow user mode to set and query the preferred
locality for the TPM chip.

Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
---
drivers/char/tpm/tpm-sysfs.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index 54c71473aa29..c43630d0996e 100644
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -309,6 +309,34 @@ static ssize_t tpm_version_major_show(struct device *dev,
}
static DEVICE_ATTR_RO(tpm_version_major);

+static ssize_t preferred_locality_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tpm_chip *chip = to_tpm_chip(dev);
+
+ return sprintf(buf, "%d\n", chip->pref_locality);
+}
+
+static ssize_t preferred_locality_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct tpm_chip *chip = to_tpm_chip(dev);
+ unsigned int locality;
+
+ if (kstrtouint(buf, 0, &locality))
+ return -ERANGE;
+
+ if (locality >= TPM_MAX_LOCALITY)
+ return -ERANGE;
+
+ if (tpm_chip_preferred_locality(chip, (int)locality))
+ return count;
+ else
+ return 0;
+}
+
+static DEVICE_ATTR_RW(preferred_locality);
+
static struct attribute *tpm1_dev_attrs[] = {
&dev_attr_pubek.attr,
&dev_attr_pcrs.attr,
@@ -321,11 +349,13 @@ static struct attribute *tpm1_dev_attrs[] = {
&dev_attr_durations.attr,
&dev_attr_timeouts.attr,
&dev_attr_tpm_version_major.attr,
+ &dev_attr_preferred_locality.attr,
NULL,
};

static struct attribute *tpm2_dev_attrs[] = {
&dev_attr_tpm_version_major.attr,
+ &dev_attr_preferred_locality.attr,
NULL
};

--
2.39.3